Improvement in blast-furnaces



c. PLAGGE; BLAST FURNACE.

NM179,342,- patented :une zv,1a'1e.

UNITED Sr us IMPROVEMENT iN BLAST-FURNACES.

" Speciicaton forming part of Letters Patent No. 179,342, dated June 27, 1876; application filtd October 7, 1875. 1 L' To all whom 'it 'may concern:

Beit known that I, CHARLES PLAGGE, of'

, the city, county, and State of New York, have invented, auew and useful Improvement in Treating Metallic Orcs, which improvement is fully set forth in the following specilicatiom reference being had'to the accom panyiug drawing, in Which- Figure 1- represents a side elevation ot' the furnace which I use in carryiu g out my invention. Fig. 2 is avertical section ofthe same.

Similar letters indicate corresponding parts.

The object of my invention is to utilize liquid, vaporized, or gaseous hydrocarbons for the reduction and smelting of metals inl blast-furnaces in amore economical and effective man` ner than heretofore practiced. v

By analysis, calculation, and experiments I have-found that a more intense and more and better metal is obtained by using 80.5 pounds of petroleum or other hydrocarbons, if fortyseven pounds thereof are burned, to carbonio acid and water, while the balance of 33.5 pounds is reserved forthe reduction ot' the metal, than are .bbtained by the combustion of one hundred pounds of petroleum to car Y bonic oxide and Water.

' Instead of introducing the liquid, vaporized, or gaseous hydrocarbons together with the blast exclusively into the hearth 'or combustion-chamber of the furnace, I divide the blast and the hydrocarbons in such manner lthat into the hearth only that part is injected which is wanted to produce the heat required for the smeltiug of the metal and slag material, while the balance of the hydrocarbon and blast required for the heating, roasting, and reducing ofthe ore is introduced into the upper part (reducing-chamber) of the furnace.

The meanswhich I have employed for car rying out my invention arerepreseuted in the drawing, in which- The letter A designates a blast-furnace, into which liquid, vaporized, or gaseous hydrocarbons (such as petroleum, tar, or natural gas from gas-Wells) are introduced by a pipe, B. Vhen a liquid hydrocarbon is used this pipe connects with a suitable supply-tank, by preference situated at an elevation above the'furnace, so that the liquid descends with a certain head, or the gaseous or liquid hydrocarbon may Je driven into tliefurnace by any suitable forcing apparatus. The pipe B is provided with a branch pipe, B0, which extends down through the top of the furnace into the reduction-chamber, or to such a depth as experience will show to'be most advantageous; The descending portion of the pipe Bn is protected against the. destructivenheat by a tube, O, 0f larger diameter, leaving an annular space for the circulation of hot or cold blast, which is injected through thc blast-pipel l). rlhe pipe C is open at its bottom end, and it is surrounded by ajacket, E, closed below, and open at the top, just above which is located a detlector, Cf, attached to the pipe C, so that the blast has to pass clear down through the'pipe Q, and then up through the jacket E, before it can escape-into the furnace, the escape taking place at a certain depth below the upper surface of the charge, but above the point at which the Hydrocarbon vapors enter into the reducing zone or chamber of the-furnace. rlhe jacket E may be protected by a fire-proof coating and the outletsof the blast and of the hydrocarbon vapors. By this arrangement the blast introduced into the upper part of the furnace acts as a protection of the hydrocarbon-pipe, and `it also serves to burn all hydrocarbon vapor or gas which may not have been utilized in the reduction of the ores. Its`free oxygen also combines with deleterious admixtures ot' the ore and flux, and the heat thereby genetrated assists to expel the carbonio acid and moisture ofthe charges, and prepares the same for the reducing-'zone The hydrocarbon-pipe B' connects also with tuyeres (one or more) F, which enter the combustion-chamber or hearth of the furnace, and which, in the cxample shown inthe drawing, can be made to communicate with the blast-pipe, or, if desired, the hydrocarbons may 'be introduced separate from the blast; lVhcn this `is done I introduce the hydrocarbons at a levcl"solne what below the level where thc blast enters, thereby securing a complete combustion ot' the hydrocarbons, and avoiding the danger of oxidizing a part of the metal by the action of The hydrocarbons may be made to enter the various zones ot' the blast-furnace either by their own gravity under pressure, or by e i l 179,34?

means' of injectors',`pmnps, or other devices suitable for this purpose.

The advantages of Iny invention are as follows: First, a great economy in fuel, on acl count of its perfect combustion witlrthe least amount of blast, the high temperature in the zone of combustion, and the utilization of the waste heat for roasting and preparing the new charges for theredueing-zone; second, a large inerease in the daily voutput of metal, since the'reducing'capacity of the furnace is largely increased, no solid fuel being mixed with the charges, and the reduction and smeltingv down or the charges being quickened by the ener# getie action ofthe hydrocarbons; third, a superior quality of 'the metal is produced, be-

cause most or'v the impurities of the ore and iux are eliminated by the preliminary roasting before the charges enter the zone of reduction, and on account of the low teniperature at which the. reduction takes place, the reduced and carboni'zed metal on its way toward the hearth coming in contact only with neutral or slightly oxidizing,r or reducing gases (as the case may require) cannot absorb iinpurities from the slag material, since it requires a high temperature and highly deoxidizing gases for their reduction; fourth, the

` liquefaction of the metal and slag material in the hearth is not retarded by the heat-absorb- 'ing reduction of carbonic acid to carbonicoxid'e,which is the case when hydrocarbons are introduced ,exclusively into the hearth'. as

blast-furnace is brought under easy control by the introduction of the hydrocarbons and heat to the various zones of the furnace, and in treating'iron ore, for instance, I am enabled to produce not only iron ot" alinost any desired also steel or iron manganese from manganiferous iron ores, which requireI high heat and .powerfulreducing agents; sixth, Where natural gas from gas-wells ot' sulicient pressure can be obtained the natural force of lthe gas serves to produce the necessary blast for the reduction and smelting of the ores, and in.. jectors operated by the gas itself may be substituted for the blast-engines; seventh, no solid fuel having to be handled a great saving inlabor is elfected.

What l claim-as new, and desire to secure by Letters Patent, is

The combination, with a blast-furnace, of a pipe7 B0, entering through the top ot' the furn'ace, and projecting down into the vreducingzone thereof, and the blast-tube C, jacket E, and deflector C, all constructed and operating substantially as described.

In testimony that I-claim the foregoing I have hereunto set my hand and seal this 4th day of October, 1875.

CHAS. PLAGGE. [L. 8.] Witnesses: W. HAUF,

RoBT. E. MILLER.

heretofore practiced; fth, the Working of the degree of earbonization and greatA purity, but y 

